1. Field of the Invention
The invention pertains to a apparatus for simulating the effects of printing process-relevant setting commands on an image to be printed.
2. Description of the Related Art
In practice, a reference pattern prepared on a color ink-jet printer is generally used as a color reference during the fulfillment of a printing order on a printing press, such as on a web-fed rotary press or on a sheet-fed press, where the press operator compares the copies printed on the printing press with this reference pattern. Such reference patterns printed on a color ink-jet printer are also called “hard proofs”.
It is also known according to the state of the art that, in addition to or in replacement of the reference pattern prepared on the color ink-jet printer, the color reference can be displayed on a true color monitor, where for this purpose print-specific image data of the image to be printed as defined in a CMYK source color space are transformed into display data, which are defined in an RGB target color space. The display of the color reference on a true color monitor is also referred to as a “soft proof”.
The transformation of the image data present in the CMYK source color space into display data defined in the RGB target color space is also called “color space transformation”. A color space transformation of this type can be carried out in the way described in U.S. Pat. No. 4,639,770.
By transforming the image data of the CMYK source color space to display data of the RGB target color space, the color reference for the printing order to be printed can be visualized on a true color monitor, which guarantees that a good impression can be obtained of the print quality to be expected of the copies to be printed. If, however, during the printing operation on the printing press, it is necessary to adjust the color result of the printed copies by entering process-relevant setting commands on the printing press, it is not possible to change the color reference visualized on the true color monitor and therefore also impossible to simulate in advance, by changing the color reference, the effects which such printing process-relevant setting commands will have on the printing press before they are actually applied. Therefore, to optimize a printing order, printing process-relevant setting commands are made in practice while copies are being printed, i.e., as the printing press is running. If the entered printing process-relevant setting commands do not lead to the desired result, spoiled copies are printed with the waste of both substrate and printing ink, which ultimately leads to a considerable increase in cost. In spite of increasing standardization, it is often necessary to make changes to the print image of an order to be printed. This can be explained in part by the fact that the fine-tuning of a print order is not accomplished until the work is being carried out in the printing plant. There is therefore a need for a device by means of which the effects of printing process-relevant setting commands on an image to be printed can be reviewed or simulated independently of the actual process of printing the image on a printing press.